How does Warren use allusion in the novel, At Heaven’s Gate?

The novel makes some use of literary allusion, not only in its title, which is taken from Shakespeare. Warren abandoned his original title And Pastures New (from Milton) because the Shakespeare tide seemed to suggest a more ironic and tragic work. Slim Sarrett, a bisexual literary opportunist who deceives all in the early sections and works a major deception on Sue before murdering her, is attracted to Elizabethan and Jacobean drama, and he sometimes appears to be a character drawn from John Marston (1574-1634) or John Webster (1580?1652?).